1. Field of the Invention
This invention relates to a variable capacity swash plate compressor, and more particularly to a variable capacity swash plate compressor having a construction which is improved in slidability between a retainer of shoes and a retainer support plate supporting the retainer.
2. Description of the Prior Art
FIG. 1 shows the whole arrangement of a conventional variable capacity swash plate compressor.
The conventional variable capacity swash plate compressor includes a drive shaft 105, a thrust flange 140 fixedly fitted on the drive shaft 105, for rotation in unison with the drive shaft 105, a swash plate 110 which is tiltably and rotatably mounted on the drive shaft 105 via a hinge ball 109, for rotation in unison with the thrust flange 140, a plurality of pistons 107 slidably received in respective cylinder bores 106, a plurality of shoes 150 arranged on a sliding surface 110a of the swash plate 110, for relative rotation with respect to the swash plate 110 according to the rotation of the drive shaft 105, a retainer 153 retaining the shoes 150, and a plurality of connecting rods 111.
Each connecting rod 111 has one end portion 111a, spherical in shape, slidably held in the shoe 150, for relative rotation with respect to the shoe 150, and the other end portion 111b secured to the piston 107.
FIG. 2 shows a view of the swash plate 110 taken from a rear side of the compressor.
The retainer 153 has its outer peripheral portion formed with a plurality of broken semi-annular portions 160 along its circumference through each of which a protruding portion 150a of each shoe 150 protrudes toward the piston 107. The retainer 153 is supported or held by a retainer support plate 155 which is fixed to a boss 110b of the swash plate 110 by bolts 154, such that the retainer 153 can perform relative rotation with respect to the swash plate 110.
Torque of an engine, not shown, installed on an automotive vehicle, not shown, is transmitted to the drive shaft 105. Torque of the drive shaft 105 is transmitted from the thrust flange 140 to the swash plate 110 via a linkage 141 to cause rotation of the swash plate 110.
The shoe 150 performs relative rotation on the sliding surface 110a of the swash plate 110 with respect to the swash plate 110, whereby torque transmitted from the swash plate 110 is converted into reciprocation of the piston 107. As the piston 107 reciprocates within the cylinder bore 106, the volume of a compression chamber within the cylinder bore 106 changes, whereby suction, compression and delivery of refrigerant gas are carried out sequentially. The inclination of the swash plate 110 changes with pressure within a crank case 108 in which the swash plate 110 is received, so that high-pressure refrigerant gas is discharged in an amount or volume corresponding to an inclination of the swash plate 110.
The retainer 153 performs relative rotation (or sliding) with respect to the swash plate 110 while receiving tensile forces of pistons 107 in the suction stroke for drawing refrigerant gas into compression chambers, which acts on corresponding portions of one face 153a (inner surface) of the retainer 153. The retainer support plate 155 supports or holds the retainer 153 in a state held in surface contact with a whole central portion of the one face 153a of the retainer 153. Therefore, the conventional variable capacity swash plate compressor suffers from the inconvenience that when conditions of lubrication get worse, abrasion occurs between sliding contact portions of the retainer 153 and the retainer support plate 155, and untoward noises are generated.